Tag: viruses

The Australian black flying-fox (Pteropus alecto) was one of the bat species whose genome was sequenced in the study.

Bats are pretty impressive critters. They are notorious for carrying viruses like Ebola and SARS, but somehow avoid getting these diseases themselves. They are the only mammal that can fly, and they live far longer than other mammals their size. What’s their secret? Researchers in Australia sequenced two different bat genomes and found that these unique bat characteristics are not only genetically linked, but may help in the treatment of human diseases.

By inserting a genetically modified virus into a guinea pig’s heart, researchers have come up a new kind of pacemaker.

Of the billions of cells in the human heart, a mere 10,000 pacemaker cells—collectively called the sinoatrial node—are responsible for sending the electrical pulse through the remaining heart cells. Pacemaker cells are differentiated in the embryo, but with age and disease their beating can speed up, slow down, become irregular, or even stop. In these instances doctors would normally implant a pacemaker to jolt the heartbeat back into line when needed. But these electronic devices can break, run out of batteries, introduce infection or be outgrown.

Bacteria sometimes commit suicide for the good of the group. When a virus infects a bacterium, the cell kills itself rather than allow the virus to replicate inside it and spread to the surrounding bacteria.

The way this works is that when viruses aren’t around, the bacteria manufacture both a bacterial cyanide pill—a toxin molecule they could use to wipe themselves out if they come under attack—and an antitoxin molecule that keeps the toxin in check. When a virus infects the bacterium, the toxin is released, kills the bacterial cell, and prevents the virus from spreading to other cells. It’s bad for the individual bacterial cell but good for the community—and certainly bad for the infecting virus. Now researchers have found a virus that manipulates this mechanism for its own means, saving itself by keeping its host bacteria from cellular suicide.

A new paper in The Lancet takes a look at the very best data on the prevalence of infection-caused cancers and comes up with some striking numbers. Overall, they estimate that 16% of cancer cases worldwide in 2008 had an infectious cause—2 million out of 12.7 million.

It’s not often that a scientist will say “mythological beast” with a straight face, but that’s exactly what virologist Ken Stedman toldNature News about a new virus. In a recent paper in Biology Direct, Stedman and his research team describe a genetic sequence that suggests the existence of a DNA-RNA chimera virus.

RNA and DNA viruses, referring to the type of nucleic acid they use to store genetic information, are two very distinct groups—probably more evolutionary distant than a lion and a snake. That’s why researchers were so surprised when they found a DNA virus sequence encoding a protein only ever found in RNA viruses. The sample came from a Lassen Volcanic National Park hotspring, where viruses prey on the bacteria living in the acidic water.

What’s the News: Clearly, as anyone suffering through a cold right now can tell you, our immune systems aren’t all they could be when it comes to keeping us disease-free. And what’s worse, the same viruses that have some people hawking up phlegm for weeks can give their roommates or spouses no more than a brief sniffle, hammering home the fact that the immune system wealth isn’t distributed evenly. Why hasn’t evolution dealt with this problem already and given us all impenetrable defenses?

As it turns out, it’s not just that evolution takes its own sweet time. It’s also that a species benefits from having individuals be immune to some things and vulnerable to others, a new study shows.

Booze inhibits more than just your judgement: it impairs your immune system’s ability to fight off pathogens, according to a study published last week in the journal BMC Immunology. Researchers exposed human monocytes, a type of white blood cell vital for a functioning immune system, to an amount of alcohol equivalent to a blood alcohol concentration of 0.1 (around the legal level in most states). Compared to booze-free cells, monocytes exposed to both short- and long-term levels of alcohol produced significantly less type 1 interferons, chemicals the help recruit immune cells to stage an antiviral response (and also have anti-tumor activity). Excessive drinking has long been thought to interfere with the body’s ability to fight disease, and boozing is an important risk factor for hepatitis C and barrier to treatment in HIV. But not much had been known about the mechanisms behind the effect.

What’s the News: Scientists have developed a new carbon nanotube device (pictured above) that’s capable of detecting single cancer cells. Once implemented in hospitals, this microfluidic device could let doctors more efficiently detect the spread of cancer, especially in developing countries that don’t have the money for more sophisticated diagnostic equipment. Any improvement in detecting cancer’s spread is important, says MIT associate professor of aeronautics and astronautics Brian Wardle, because “of all deaths from cancer, 90 percent are … from tumors that spread from the original site.”

What’s the Context:

The researchers’ original microfluidic device from four years ago featured tens of thousands of microscopic silicon posts coated with tumor-sticking antibodies: when cancer cells bumped into the posts, they’d stick. But if cancer cells didn’t bump into a silicon post, they’d go undetected. The group says their new version is eight times better.

This new dime-sized microfluidic machine works in the same way, but the solid silicon tubes were switched out for highly porous carbon nanotubes. This allows the blood to actually flow through the tubes instead of just around them, increasing the likelihood of catching a cancer cell.

Not So Fast: The process of commercializing a technology like this takes quite a while; the previous version from four years ago is being tested in hospitals now and is may be commercially available “within the next few years.”

Next Up: The scientists are currently tweaking the device to try to catch HIV.